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Lesson Topics Discussion Quiz: Class Homework

Example1

Title: Algebra

Grade Lesson s5-p2

Explanation: The best way to understand PSAT-4 is by looking at some examples. Take turns and read each example for easy understanding.

Examples

Topics → Definition Example1 Example2

Step: 1

The given system of equations are:

15x + 21y = 24 ---- equation(1)
28y = -20x + 32 ---- equation(2)

Let’s solve for y in terms of x from equation(2): \$y = (-20 x + 32)/(28)\$.
Then simplify the above equation \$y = (-5x + 8)/7\$.

Explanation:

Here the equation (2) is simplified in the y terms.

Step: 2

Now, let’s substitute this expression for y into equation(1):

\$15x + 21(-5x + 8/7) = 24\$

Now, solve for x:

\$15x - (105x)/7 + (168)/7 = 24\$

Then simplify:

\$15x - 15x + 24 = 24\$
24 = 24

This equation doesn’t make sense, as it implies 24 = 24, which is always true. This indicates that the system of equations is dependent, meaning there are infinitely many solutions.

Explanation:

Then here we plug the y value simplify the equation and then solve for the x value. It implies 24 = 24, so it gives many more infinite solutions.